Replace clobber of CFLAGS in configure.ac

Replaced the clobbering of the user variable CFLAGS in configure.ac with
UNW_EXTRA_CFLAGS.

configure.ac

@@ -476,14 +476,18 @@ AC_SUBST([LIBZ])
 AM_CONDITIONAL(HAVE_ZLIB, test x$enable_zlibdebuginfo = xyes)
 
 AC_MSG_CHECKING([for Intel compiler])
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[#ifndef __INTEL_COMPILER
-#error choke me
-#endif]])],[intel_compiler=yes],[intel_compiler=no])
-
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
+        [],
+        [#ifndef __INTEL_COMPILER
+         #error choke me
+         #endif
+        ])],
+    [intel_compiler=yes],
+    [intel_compiler=no])
+AC_MSG_RESULT([$intel_compiler])
 if test x$GCC = xyes -a x$intel_compiler != xyes; then
-  CFLAGS="${CFLAGS} -fexceptions -Wall -Wsign-compare"
+    AC_SUBST([UNW_EXTRA_CFLAGS],["-fexceptions -Wall -Wsign-compare"])
 fi
-AC_MSG_RESULT([$intel_compiler])
 
 AC_MSG_CHECKING([for QCC compiler])
 AS_CASE([$CC], [qcc*|QCC*], [qcc_compiler=yes], [qcc_compiler=no])

src/Makefile.am

@@ -25,6 +25,12 @@ SOVERSION=9:0:1		# See comments at end of file.
 SETJMP_SO_VERSION=0:0:0
 COREDUMP_SO_VERSION=0:0:0
 
+AM_CPPFLAGS = $(UNW_DEBUG_CPPFLAGS) \
+              $(UNW_REMOTE_CPPFLAGS) \
+              $(UNW_TARGET_CPPFLAGS) \
+              -I$(top_srcdir)/include -I$(top_srcdir)/include/tdep-$(arch) -I.
+AM_CFLAGS = $(UNW_EXTRA_CFLAGS)
+
 #
 # Don't link with start-files since we don't use any constructors/destructors:
 #
@@ -1243,10 +1249,6 @@ libunwind_la_LDFLAGS =	$(COMMON_SO_LDFLAGS) -XCClinker -nostdlib \
 libunwind_la_LIBADD  += -lc $(LIBCRTS)
 libunwind_la_LIBADD += $(LIBLZMA) $(LIBZ)
 
-AM_CPPFLAGS = $(UNW_DEBUG_CPPFLAGS) \
-              $(UNW_REMOTE_CPPFLAGS) \
-              $(UNW_TARGET_CPPFLAGS) \
-              -I$(top_srcdir)/include -I$(top_srcdir)/include/tdep-$(arch) -I.
 noinst_HEADERS += unwind/unwind-internal.h
 
 EXTRA_DIST = $(libunwind_la_EXTRAS_ia64)

tests/Makefile.am

@@ -33,7 +33,7 @@ AM_CPPFLAGS = $(UNW_DEBUG_CPPFLAGS) \
               $(UNW_REMOTE_CPPFLAGS) \
               $(UNW_TARGET_CPPFLAGS) \
               -I$(top_srcdir)/include -I$(top_srcdir)/include/tdep-$(arch) -I$(top_srcdir)/src
-AM_CFLAGS = -fno-optimize-sibling-calls
+AM_CFLAGS = $(UNW_EXTRA_CFLAGS) -fno-optimize-sibling-calls
 
 LOG_DRIVER = $(SHELL) $(UNW_TESTDRIVER)